The field of the invention is sporting goods and the invention relates more particularly to compound archery bows. Compound archery bows have greatly facilitated the use of bows and permit the archer to pull back on the bowstring with increasing force to a let off point where the amount of force required to further withdraw the bowstring greatly deceases, which permits the archer to hold the bow in a fully drawn position with far less effort as compared to bows made before the development of the compound bow. The distance that an archer pulls back the bowstring before it stops or reaches the wall is the xe2x80x9cdraw Length.xe2x80x9d
Compound bows are discussed in detail in U.S. Pat. No. 6,250,293 and the specification and drawings of that patent are incorporated herein by reference for background purposes. It is often desired that the draw length be adjusted by the archer. Early designs of cams required that the bow be disassembled to change the draw length, which required a bow press. This prohibited the archer from changing the draw length in the field. Designs have been devised which permitted draw length adjustment without a bow press, but such designs required the removal of screws which could be easily dropped during an adjustment and the inability to find a screw if no replacement screw is available would disable the bow.
Draw stops are also provided so that once the bowstring is fully drawn, the further amount that the bowstring may be drawn is stopped by the draw stop. The adjustment of the draw stop is a highly useful feature since it provides a fine adjustment of the draw length.
It is an object of the present invention to provide an improved adjustable cam for archery bows which permit the adjustment of the draw length without the use of a bow press or the removal of one or more screws. The present invention is for an adjustable cam for an archery bow having a pair of limbs having an idler rotatingly secured at an end of an idler limb and an adjustable cam rotatingly secured at the end of the other limb. The archery bow has a bow string attached to the adjustable cam at a bow string cam end. The bowstring extends around the idler wheel and has a returning end stretch. The end stretch has an end which is also affixed to the adjustable cam. A harness string is affixed at an idler end to the idler limb and to the adjustable cam at its other end. The adjustable cam thus has three tracks comprising a bowstring or inner track, a harness or intermediate track, and an end stretch or outer track. The improvement of the present invention comprises the bowstring or inner track being formed on an inner cam body. The harness or intermediate track is formed on an intermediate cam body. The end stretch or outer track is formed on an outer cam body. The intermediate cam body is fabricated from a separate member from either of the inner or outer cam bodies. The intermediate cam body has a curved adjustment slot which captures an adjustment member which is configured to tighten the intermediate cam body against the inner cam body in order to adjust the draw length. The intermediate cam body preferably has a second curved adjustment slot which captures a second adjustment member, also configured to tighten the intermediate cam body against the inner cam body. The intermediate cam body preferably has a harness string stop slot at an end of the intermediate cam body positioned so that it captures the harness string as the bowstring is withdrawn to a fully drawn position and functions as a wall. Preferably, the harness string stop slot is adjustable by the use of a draw stop screw within the draw slot. Also preferably, the draw slot has a window along its side so that the position of the draw stop screw can be viewed by the archer.